2 lbs. chunky frozen hashbrowns
8 oz. shredded cheddar cheese
8 oz. shredded Mozzarella cheese
8 oz. sour cream
2 cans cream of mushroom soup
1 sm. can French fried onions

Mix together the hashbrowns (not shredded hashbrowns), cheeses, sour cream, soup (mushroom or celery) and 1/2 of the French fried onions. Place in a 9x13 pan. Sprinkle remaining onions on the top. Bake in 350 degree oven for 1 hour.